The present invention relates to a multi-function analog electronic timepiece comprising a first indicating means driven by an ultrasonic motor and a second indicating means driven by a motor.
As shown in FIG. 15, electrical energy from a power source 1 is supplied to an electronic circuit 2. An oscillating circuit 201 which composes the electronic circuit 2 oscillates reference signals of for example, 32,768 Hz, which is further divided into 1 Hz by a frequency dividing circuit 202.
The electronic circuit 2 generates driving pulses for driving a stepping motor 3 from 1 Hz signals from the frequency dividing circuit 202 by means of a pulse generating circuit 203 and a driving circuit 204.
The stepping motor 3 of a watch comprises a coil 301 for electromagnetically converting the driving pulses from the driving circuit 204 of the electronic circuit 2 into magnetic energy, a stator 302 for directing the magnetic energy to a rotor 302 and the rotor 303 comprising an electromagnet which rotates by receiving the magnetic energy.
Since driving torque of the stepping motor 3 is small, a pinion 304 is provided to the rotor 303 to transfer rotation torque to a transmission mechanism 4 comprising a fifth gear 405 which is a decelerating gear train. Time is indicated by attaching a second hand 503 for indicating seconds to a fifth gear 404 which rotates once in one minutes among the gear train which structures the decelerating gear train in the transmission mechanism 4, a minutes hand 502 for indicating minutes to a minute gear 402 which rotates once in one hour and an hour hand 501 to an hour wheel 401 which rotates once in 12 hours. Further, date is indicated by sending once a day a date plate 701 on which dates are printed and which is engaged with a date rotating click 704 which is attached to a date rotating gear 703 which is rotated once in 24 hours by the hour wheel 401 through the intermediary of a transmission mechanism 6 comprising a decelerating gear train.
The rotor 303, fifth gear 405 and fourth gear 404 are supported by a support member 91 and are retained by a train wheel bridge 92. A third gear 403 for transferring torque from the fourth gear 404 to a branched gear 402 is supported by a date plate maintaining plate 702 which guides the date plate 701 and is retained by the train wheel bridge 92.
However, a time necessary for the date plate 701 which structures a conventional analog electronic timepiece to be sent once in one day is about 4 hours. During about 20 hours which is remainder of one day, a date jumper 705 which engages with a gear section 7011 of the date plate 701 is provided so that the date plate 701 will not rotate erroneously by shock and others during carrying the timepiece. An adjusting section 7052 of the date jumper 705 is inserted to the gear section 7011 of the date plate 701 by elastic force of a spring section 7051 of the date jumper 705 to anchor the date plate 701. During about 4 hours when the date plate 701 is switched along a change of date, the stepping motor 3 has to rotate while receiving the load of the elastic force of the spring section 7051 of the date jumper 705.
Accordingly, an enough large energy for generating rotating torque of the stepping motor 3 to overcome the elastic force of the spring section 7051 of the date jumper 705 is necessary for the driving pulses from the electronic circuit 2 to the stepping motor 3. There has been a problem that much power is consumed and a life of a battery 11 is shortened by continuously supplying enough large energy for generating rotating torque of the stepping motor 3 to overcome the elastic force of the spring section 7051 of the date jumper 705 for about 20 hours during which the date plate 701 is not switched.
The date rotating gear 703 is rotated by rotation of the stepping motor 3 through the intermediary of a date rotating intermediate gear 601 in correcting the date plate 701 to an arbitrary date. Beside the mechanism for switching the date plate 701, a manual rotation is transferred to a date correcting gear 803 through the intermediary of a cluch wheel 802 from a stem 801 by manually rotating the stem 801. A mechanism for correcting the date plate 701 to an arbitrary date by engaging the date correcting gear 803 with the date plate 701 is also provided.
During when the date plate 701 is switched by means of the date rotating gear 703, the gear section 7011 of the date plate 701 is normally moving from a position 7011 anchored by the date jumper 705. Now the gear section 7011 of the date plate 701 is at a position 7012, and at this time, the date plate 701 is tried to be corrected to an arbitrary date by the date correcting gear 803 which is engaged with the date plate 701. Then the date correcting gear 803 and a gear section 7012 of the date plate 701 sometimes thrust each other. The date correcting gear 803 or the gear section 7012 of the date plate 701 might be broken if the date of the date plate 701 is forcibly changed to the arbitrary date.
In order to solve these problems, some analog electronic timepiece excludes the date jumper 705 by providing a stepping motor 32 for rotating only a date plate 711 on which dates are printed as shown in FIGS. 20, 21 and 22.
The stepping motor 32 for rotating only the date plate 701 comprises a coil 321, a stator 322 and a rotor 323. The rotor 323 is further provided with a pinion for transmitting rotation torque to a transmission mechanism 61 for transmitting torque to a calendar indicating mechanism 71. The provision of the stepping motor 32 obviates a large energy for generating rotation torque of the stepping motor 3 for overcoming the elastic force of the spring section 7051 of the date jumper 705 to be continuously supplied during about 20 hours when the date plate 701 is not switched.
When a date of the date plate 701 is arbitrary corrected, a coil 311, stator 312 and rotor 313 for inputting date plate correcting input signal to a control circuit 215 of the electronic circuit 2 are structured by a button 811.
The stepping motor 31 has the rotor 313. The rotor 313 is provided with a pinion 314 for transmitting rotation torque to the transmission mechanism 4 for transmitting the torque to the time indicating mechanism 5. A driving circuit 214 generates driving pulses of the stepping motor 32 for rotating only the date plate 711, beside the stepping motor 31. When the date plate correcting command signal is transmitted to the driving circuit 214, the stepping motor 32 rotates to correct to an arbitrary date.
However, since the torque which is generated by the stepping motor 32 is very small, a gear train having a large deceleration ratio has to be provided beside the gear train 4 for driving the hands. These has been a problem that the transmission mechanism 61 comprising the stepping motor 32, date rotating intermediate gear 611 and date rotating gear 612 is necessary even though the date correcting gear 803 has been obviated.
Further, since the stepping motor 31 and the stepping motor 32 are electromagnetic mechanism, they are weak to strong magnetic field from outside. The stepping motor 31 and the stepping motor 32 have to be separated by a distance "L" so that magnetic fields generated by the stepping motor 31 and the stepping motor 32, respectively, will not influence each other. Accordingly, there has been a problem that since the distance "L" is not negligible distance within a size of a small timepiece, it unavoidably enlarges the analog electronic timepiece.